Saturday

July 30, 2016
**calculus**

A fertilizer producer finds that it can sell its product at a price of p=300-x dollars per unit when it produces x units of fertilizer. The total production cost (in dollars) for x units is C(x)= 20,000+24x+0.5x^2. How many units must be manufactured to maximize the profit?
*Thursday, May 12, 2016 by Qwenie*

**Pre Calculus**

The following table shows the rate of water flow (in L/min) through a dam. t (min) 1 5 9 13 17 21 25 V'(t) (L/min) 6 6 2 2 3 6 2 Approximate the total volume of water that passed through the dam from t=1 to t=25 using Simpson's rule, with n=6.
*Thursday, May 12, 2016 by John*

**calculus 1**

Set up the simplified integral and compute the volume created when the area bounded by y=.25x4, y=4, and the y=axis (Quadrant 1) is rotated around the line x=-2
*Wednesday, May 11, 2016 by anon*

**calculus**

Set up the simplified integral and compute the volume created when the area bounded by one period of the function 3+sin(x) and the x-axis (use the endpoints of the period starting at x=0) is rotated around: a) the x-axis b) the y-axis
*Wednesday, May 11, 2016 by bean*

**Differential Calculus**

The base of an isosceles triangle is 10 feet long and the base angles are decreasing at a rate of 2° per second. Find the rate of change of the area when the base angles are 45°.
*Wednesday, May 11, 2016 by Serena*

**Calculus**

The base of an isosceles triangle is 8 feet long. If the altitude is 6 feet long and is increasing 3 inches per minute, are what rate are the base angles changing?
*Wednesday, May 11, 2016 by Claire*

**Calculus**

A building is to be braced by means of a beam which must pass over a wall. If the wall is 3 3/8 feet high and stands 8 feet from the building, find the shortest beam that can be used.
*Wednesday, May 11, 2016 by Sandra*

**Calculus**

A statue 10 feet high is standing on a base 13 feet high. If an observer's eye is 5 feet above the ground, how far should he stand from the base in order that the angle between his lines of sight to the top and bottom of the statue be a maximum?
*Wednesday, May 11, 2016 by Alexa*

**Calculus**

Find the area of the largest rectangle cut from the first quadrant by a line tangent to the curve y=e^(-x^2)
*Wednesday, May 11, 2016 by Sandra*

**Calculus**

Using l'hopitals rule, evaluate the following: Lim x-->infinity Inx/2(x)^1/2 Limx-->0 (1/x - 1/e^x -1) I tried both multiple times and I'm still not getting an answer. For the first one I tried l'hopitals rule 3 times and I'm still getting infinity over ...
*Tuesday, May 10, 2016 by Maya*

**calculus**

The volume V, in liters, of air in the lungs during a two-second respiratory cycle is approximated by the model V = 0.1729t + 0.1522t^2 − 0.0374t^3, where t is the time in seconds. Approximate the average volume of air in the lungs during one cycle. (Round your answer to...
*Tuesday, May 10, 2016 by Sam*

**calculus sir damon help me or steve**

integrate dx/root(coshx-1) plz show step
*Tuesday, May 10, 2016 by dam*

**Calculus**

Let x µ = x µ (u) be a parametric equation for the curve in pseudo-Riemannian four-space connecting points P and Q. Here u is any, not necessarily affine parameter. Assume that the derivative satisfies Update: Let x µ = x^µ(u) be a parametric equation ...
*Tuesday, May 10, 2016 by ChrismB*

**calculus**

Find dy/dx. y = x^ln x, x > 0
*Monday, May 9, 2016 by steve*

**calculus**

1. A rocket is fired vertically into the air. Six kilometers away, a telescope tracks the rocket. At a certain moment, the angle between the telescope and the ground is and is increasing at a rate of 0.6 radians per minute. (See the picture. I have defined y to be the height ...
*Monday, May 9, 2016 by dennis*

**math: pre-calculus **

You have 5 grams of carbon-14; whose half-life is 5730 years. a)Write the rule of the function that gives the amount of carbon-14 remaining after x years. b)How much carbon-14 will be left after 4,000 years? c)When will there be just 1 gram left?
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

Solve the equation. First express your answer in terms of natural logarithms (for instance, z=(2+ln5)/ln3). Then use a calculator to find an approximation for the answer. 3^x+9=2^x.
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

If current rates of deforestation and fossil fuel consumption continue, then the amount of atmospheric carbon dioxide in parts per million (ppm) will be given by f(x)=375e^0.00609c, where c=0 corresponds to 2000. a)What is the amount of carbon dioxide in 2022? b)In what year ...
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

Solve the equations. Log(6x-1) = Log(x+1) + log4
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

Let u=lnx and v=lny. Write the expression ln3√x/2y in terms of u and v. For example, lnx^3y=lnx^3+lny=3lnx +lny= 3u+v.
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

Write the expression as a single logarithm. Ln(e^3y)+ln(ey)-4
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

Let u=ln and v=ln y. Write the expression ln(5√(x3√y)) in terms of u and v. for example, lnx^3y = lnx^3+lny = 3lnx+lny = 3u+v
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

For the log function (h(x)=log(x+3)-8): a) Find the domain. b) Find the asymptotes. c) Find the x-intercepts.
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

List the transformations that will change the graph of g(x)=lnx into the graph of the given function h(x)=log(x+3)-8 a) Horizontally shift the graph to the right by 3; then vertically shift downward by 8. b) Horizontally shift the graph to the left by 8; then vertically shift ...
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

Evaluate the expression without using a calculator. Unless stated otherwise, all letters represent positive numbers. e^(ln√x+5)
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

The Department of Commerce estimated that there were 53 million internet users in the country in 1999 and 90 million in 2002. Find an exponential function that the models the number of Internet users in year x, with x=0 corresponding to 1999.
*Sunday, May 8, 2016 by Nicky*

**math: pre-calculus **

5. For the log function (h(x)=log(x+3)-8): a) Find the domain. b) Find the asymptotes. c) Find the x-intercepts.
*Sunday, May 8, 2016 by Nicky*

**Calculus**

using implicit differentiation find the equation of the tangent line to the graph of the following function at the indicated point x^2 y^3 -y^2+xy-1=0 at (1,1)
*Sunday, May 8, 2016 by ChrismB*

**Calculus **

Water is draining from a swimming pool in such a way that the remaining volume of water after t minutes is V = 200(50 - t)^2 cubic meters. Find : (a) the average rate at which the water leaves the pool in the first 5 minutes
*Sunday, May 8, 2016 by Posul Sioni *

**calculus**

Find the limit lim x ->0 (sin^2 2x)/(x^2)
*Sunday, May 8, 2016 by Anonymous*

**calculus**

evaluate the definite integr 2 ∫ (x+1/x)² dx 1
*Sunday, May 8, 2016 by Anonymous*

**calculus**

the marginal cost function for widgets is dr/dq= 0.001Q^2+0.01Q+10 total fixed xosts equal $500 part 1= convert the marginal cost function into total cost function. part 2= determine total costs when Q=100.
*Sunday, May 8, 2016 by Alcina*

**calculus**

evaluate the definite integrals 1 ∫ root(1+3x) dx 0
*Sunday, May 8, 2016 by Jay*

**calculus**

evaluate the definite integr 2 ∫ 5/(3+2x) dx 0
*Sunday, May 8, 2016 by Jay*

**calculus help amigos**

Find the point on the line 5x+5y+7=0 which is closest to the point (3,−4)
*Saturday, May 7, 2016 by AMELIA*

**calculus help**

integrate:dx/(3x^3-5)^3 i don,t know how to use wolframalpha plz show me step....
*Saturday, May 7, 2016 by philip*

**differential calculus**

Beth leaves Muskegon, 30 mile north of Holland, traveling at 60 mph. Alvin leaves Holland traveling north at V=20t+40 mi/hr. When will Alvin pass Beth? How far from Holland will they be? :I think Beth's distance is d=60t-30 (using Holland as the frame of reference). Should...
*Saturday, May 7, 2016 by Yo*

**integral calculus**

help me integrate dx/(3x^3-5)^3 thanks
*Saturday, May 7, 2016 by philip*

**Calculus**

Use the Midpoint Rule with n = 4 to approximate the area of the region bounded by the graph of the function and the x-axis over the given interval. f(x) = x^2 + 4x, [0, 4]
*Saturday, May 7, 2016 by Sam*

**Calculus**

Farmer Jones, and his wife, Dr. Jones, decide to build a fence in their field, to keep the sheep safe. Since Dr. Jones is a mathematician, she suggests building fences described by y=4x^2 and x^2+10. Farmer Jones thinks this would be much harder than just building an enclosure...
*Friday, May 6, 2016 by Chris*

**Calculus**

A bucket begins weighing 30 pounds, including the sand it holds. The bucket is to be lifted to the top of a 25 foot tall building by a rope of negligible weight. However, the bucket has a hole in it, and leaks 0.1 pounds of sand each foot it is lifted. Find the work done ...
*Friday, May 6, 2016 by David*

**calculus**

calculus. suppose dR/dt= (d/R)^(2) and P(1) 4. separate the differential equation, integrate both sides
*Friday, May 6, 2016 by Aishwarya*

**calculus help**

integrate:dx/(3x^3-5)^3 help plz show step
*Friday, May 6, 2016 by samuel*

**calculus help**

Integrate:(3x^5-5)^-3 dx thanks
*Friday, May 6, 2016 by dam*

**calculus**

find the derivative of d^2x/dt^2 if x^3=at^2 thanks
*Friday, May 6, 2016 by philip*

**Pre calculus **

Find the value for sin(theta), cos(2 theta)=3/4 and 270 degrees<0<360 degrees
*Thursday, May 5, 2016 by Leslie*

**calculus help me plz**

integrate:dx/((x-1)sqrt(x^2-2) a tutor here direct me to a page but i do not know how to use it i tried but it did not show me any step...i need help plz
*Thursday, May 5, 2016 by samuel!!!!*

**calculus plz help me**

integrate:dx/((x-1)sqrt(x^2-2) plz show solution i plead
*Thursday, May 5, 2016 by samuel*

**Calculus**

approximate the change in the lateral surface area(excluding the area of the base of a right circular cone of fixed height of h=6m when its radius decreases from r=11m to r=10.9m S=(pi)r sqrt(r^2+h^2)
*Thursday, May 5, 2016 by TK*

**Math**

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be? A. Symmetric with little variation B. Symmetric with large variation C. Skewed right with ...
*Wednesday, May 4, 2016 by angela*

**Math**

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be? A. Symmetric with little variation B. Symmetric with large variation C. Skewed right with ...
*Wednesday, May 4, 2016 by angela*

**Math**

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be? A. Symmetric with little variation B. Symmetric with large variation C. Skewed right with ...
*Tuesday, May 3, 2016 by angela*

**Math**

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be? A. Symmetric with little variation B. Symmetric with large variation C. Skewed right with ...
*Tuesday, May 3, 2016 by angela*

**Calculus**

Use Simpson's rule with n = 4 to approximate. Keep at least 2 decimal places accuracy. Integrate: (cos(x))/(x) x=1 to 5
*Tuesday, May 3, 2016 by Dave*

**Calculus**

Use the trapezoidal rule with n = 5 to approximate. Keep at least 2 decimal places accuracy. Integrate: (cos(x))/(x) from x=1 to 5
*Tuesday, May 3, 2016 by Jack*

**Calculus 3**

I need help writing the series 4 + 1/5 + .3 + 1/(3 + sqrt 2) + 1/(9+ sqrt 3) + 1/(27 + sqrt 4) + 1/(81 + sqrt 5 .... I have played with using irrational numbers, natural log and a vast variety of exponential arrangements. Any help to get me going in the right direction would ...
*Tuesday, May 3, 2016 by Sheila*

**calculus**

A hot air balloon is rising vertically upward from the ground. The crew of a boat from a nearby lake notices this situation and looks upward at an angle of 10 degree to see the balloon. If the boat is 400meters away from the balloon, and the angle of observation is changing at...
*Tuesday, May 3, 2016 by rhakesh*

**Calculus**

Approximate the change in the lateral surface area(excluding the area of the base) of a right circular cone fixed height of h = 6m when its radius decreases from r=9m to r=8.9m (S=(pi)r sqrt(r^2+h^2)).
*Tuesday, May 3, 2016 by Jenna*

**Pre-calculus**

Consider an open-top box constructed from an 8.5 × 11 inch piece of paper by cutting out squares of equal size at the corners, then folding up the resulting flaps. Denote by x the side-length of each cut-out square. a) Draw a picture of this construction, and find a ...
*Monday, May 2, 2016 by Arian*

**calculus**

rewrite each summation using the sigma notation. Do not evaluate the sums (a)3 + 4 + 5 + . . . + 93 + 94 (b)9 + 16 + 25 + 36 + . . . + 14
*Monday, May 2, 2016 by Jay*

**calculus**

You own a small airplane that holds a maximum of 20 passengers. It costs you $100 per flight from St. Thomas to St. Croix for gas and wages plus an additional $6 per passenger for the extra gas required by the extra weight. The charge per passenger is $30 each if 10 people ...
*Monday, May 2, 2016 by Jay*

**calculus**

Find the dimensions of the rectangle with the largest area if the base must be on the x-axis and its other two corners are on the graph of: (a) y=16-x²,-4<=x<=4 (b)x²+y²=1 (c)|x|+|y|=1 (d)y=cos(x),-pi/2<=x<=pi/2
*Monday, May 2, 2016 by Jay*

**calculus**

Evaluate lim (1³ +2³ +3³ +…+ n3)/n^4 n →∞ by showing that the limit is a particular definite integral and evaluating that definite integral.
*Monday, May 2, 2016 by Jay*

**calculus**

Evaluate π ∫ tan² x/3 dx 0
*Monday, May 2, 2016 by Jay*

**calculus**

Use the Fundamental Theorem of Calculus to find G'(x) if: G(x)=∫ up(x²) bottom(1) cost dt
*Monday, May 2, 2016 by Jay*

**calculus**

Use the Fundamental Theorem of Calculus to find G'(x) if: /x² G(x)= / cos t dt / 1
*Monday, May 2, 2016 by Jay*

**calculus**

I'm having trouble on this question: Find the area of the region in the first quadrant that is bounded above by the curve y= sq rt x and below by the x-axis and the line y=x -2.
*Monday, May 2, 2016 by Jay*

**Calculus**

A conical cistern is 10 ft. across the top and 12 ft. deep. If water is poured into the cistern at the rate of 1 cubic foot per second, how fast is the surface rising when the water is 8 ft. deep?
*Monday, May 2, 2016 by Claire*

**Calculus**

A particle travels along the parabola y=ax^2+x+b. At what point do its abscissa and ordinate change at the same rate?
*Monday, May 2, 2016 by Alexa*

**Calculus**

A light hangs 15 ft. directly above a straight walk on which a man 6 ft. tall is walking. How fast is the end of the man's shadow travelling when he is walking away from the light at a rate of 3 miles per hour?
*Monday, May 2, 2016 by Sandra*

**calculus too hard help**

if y=x^x^x^x... dy/dx=? plz show working thanks got no ideal at all
*Monday, May 2, 2016 by sam*

**Calculus - urgent**

A lamina. defined by y>=0 with edges y=0, y=3/2(1-x^2) and x=-y+2y^2, for which the density is given by p(x,y)=y. a) define domain as union of type 1 and type 2 region. b) Calculate mass of lamina.
*Monday, May 2, 2016 by Alex*

**calculus**

Given the area is in the first quadrant bounded by y²=x, the line x=4 and the 0X What is the volume generated when this area is revolved about the 0X? the answer is 25.13 but I don't know how. help me please
*Sunday, May 1, 2016 by ced*

**Calculus**

A cardioid r=1+cos(theta) A circle r=3*cos(theta) a) Define the domain of the region enclosed inside both the cardioid and the circle. b) Use polar coordinates to calculate the area. (We can use symmetry about x-axis)
*Sunday, May 1, 2016 by Alex*

**Calculus**

Air expands adiabatically in accordance with the law PV^1.4=Const. If at a given time the volume is 14 cubic feet and the pressure is 40 pounds per square inch, at what rate is the pressure changing when the volume is decreasing 1 cubic foot per second?
*Sunday, May 1, 2016 by Alexa*

**Calculus**

One ship is sailing south at a rate of 5 knots, and another is sailing east at a rate of 10 knots. At 2 P.M. the second ship was at the place occupied by the first ship one hour before. At what time does the distance between the ships not changing?
*Sunday, May 1, 2016 by Sandra*

**Calculus**

An island is 3 mi from the nearest point on a straight shoreline; that point is 6 mi from a power station. A Utility company plans to lay electrical cable underwater from the island to the shore and then underground along the shore to the power station. Assume ...
*Saturday, April 30, 2016 by Laura*

**Calculus**

Optimization: A man on an island 16 miles north of a straight shoreline must reach a point 30 miles east of the closet point on the shore to the island. If he can row at a speed of 3 mph and jog at a speed of 5 mph, where should he land on the shore in order to reach his ...
*Saturday, April 30, 2016 by Sammy*

**calculus**

Assume that the radius ,r , of a sphere is expanding at a rate of 10in./min. The volume of a sphere is V=43πr^3. Determine the rate at which the volume is changing with respect to time when r=5in. The volume is changing at a rate of how many in^3/min.?
*Saturday, April 30, 2016 by Marquese*

**Calculus**

Find the area of the largest rectangle having one side on the x-axis and inscribed in a triangle formed by the lines y=x, y=0 and 3x+y=20.
*Saturday, April 30, 2016 by Sandra*

**Calculus**

Find the area of the largest rectangle with sides parallel to the coordinate axes which can be inscribed in the area bounded by the two parabolas y=26-x^2 and y=x^2+2
*Friday, April 29, 2016 by Alexa*

**Calculus**

An object's velocity after t seconds is v(t)= 38-2t feet per second. a. How many seconds does it take for the object to come to a stop (velocity = 0)? b. How far does the car travel during that time? c. How many seconds does it take the car to travel half the distance in ...
*Friday, April 29, 2016 by Adam*

**Calculus**

A bucket begins weighing 15 pounds, including the sand it holds. The bucket is to be lifted to the top of a 50 foot tall building by a rope of negligible weight. However, the bucket has a hole in it, and leaks 0.1 pounds of sand each foot it is lifted. Find the work done ...
*Friday, April 29, 2016 by Joey*

**College Algebra/pre-calculus**

The question is to evaluate each logarithm: My professor wants us to show work. Could you please tell me if I'm on the right track? Thank you!!! 1. log6^(1/36)= -2 2. ln(1/e^4)= 1/e^2 3. log7^1= 0 4. log4^64= ln64/ln4= 3 5. log10^8= ln8/ln10= .9031 6. log3^(radical 3)= I ...
*Friday, April 29, 2016 by Need Help*

**Pre Calculus**

A cylinder shaped can needs to be constructed to hold 200 cubic centimeters of soup. The material for the sides of the can costs 0.02 cents per square centimeter. The material for the top and bottom of the can need to be thicker, and costs 0.06 cents per square centimeter. ...
*Friday, April 29, 2016 by Joey*

**Pre Calculus**

A piece of cardboard measuring 13 inches by 11 inches is formed into an open-top box by cutting squares with side length x from each corner and folding up the sides. a. Find a formula for the volume of the box in terms of x b. Find the value for x that will maximize the volume...
*Friday, April 29, 2016 by Joey*

**Calculus**

Find the dimensions of the largest right circular cylinder that can be inscribed in a sphere of radius 6 inches.
*Thursday, April 28, 2016 by Sandra*

**Calculus**

An open box is formed from a piece of cardboard 12 inches square by cutting equal squares out of the corners and turning up the sides, find the dimensions of the largest box that can be made in this way.
*Thursday, April 28, 2016 by Alexa*

**Math, Pre-Calculus.**

A postal airplane leaves lsland A and flies 91 miles to Island B. It drops off and picks up mail and flies 63 miles to lsland C. After unloading and loading A- mail, the plane returns to lsland A at an average rate of 300 miles per hour. How long does it take the pilot to ...
*Thursday, April 28, 2016 by Daniel López*

**Calculus**

Evaluate as limit approaches 0. (Without using l'hopital's rule. ( Sqrt(4+sin(x))-2 ) / (3x)
*Thursday, April 28, 2016 by Brian*

**Calculus**

find the point on the plane 5x+4y+z=12 that is nearest to (2,0,1)
*Thursday, April 28, 2016 by Lyndsay*

**Pre-Calculus**

suppose y is directly proportional to x. if y=6 when x=4, find the constant of proportionality and write the formula for y as function of x. Use your formula to find x when y=8.
*Wednesday, April 27, 2016 by Monica*

**Calculus **

Find the 4th Taylor polynomial, P4, generated by f(x) = 1/x at center a = 2 ?
*Wednesday, April 27, 2016 by ChrismB*

**Calculus**

Sketch the region enclosed by the curves given below. Decide whether to integrate with respect to x or y. Then find the area of the region. y=4cos(x),y=4−8x/π. I thought it was the integral of 4cos(x)- the integral of 4- 8x/π on the interval 0 to π/2. This...
*Wednesday, April 27, 2016 by Kevin*

**pre-calculus**

Rewrite the following expression as an algebraic function of x sin(arccos(x/2)) I know sine is y, which is opposite over hypotenuse. I also know that arccos is the inverse of cosine. I'm confused on what the question is asking and what to do with the x. Please help! Thanks
*Wednesday, April 27, 2016 by Em*

**Calculus**

Find the 4th Taylor polynomial, P4, generated by f(x) = 1/x at center a = 2 ?
*Wednesday, April 27, 2016 by ChrismB*

**Calculus**

give a parametrization of the ellipse x^2/25 + y^2/9 =1 that travels once counter clockwise in an interval at belongs to (0, 2pi)?
*Wednesday, April 27, 2016 by ChrismB*

**calculus**

A rectangular closed box with a square base is to have a capacity of 27 cubic inches determine the least amount of material required.
*Wednesday, April 27, 2016 by gillian*

**calculus**

What are the dimensions of a rectangular field of area A that requires the least amount of fencing.
*Wednesday, April 27, 2016 by gillian*

**calculus**

A rectangular lot has a perimeter of 320meters determine the maximum area of the lot
*Wednesday, April 27, 2016 by gillian*